A fine needle biopsy normally uses a thin hollow needle to remove a small tissue sample from an organ or a tumour. A common type of fine needle biopsy is a fine needle aspiration, where a fine needle and a syringe are used to remove either fluid from a cyst or clusters of cells from a solid mass. The procedure for fine needle aspiration and fine needle biopsy is basically the same, and the two procedures are sometimes performed together.
Fine needle biopsies can be obtained from organs or tumours located within the human anatomy. Common sites that may be considered for biopsy procedures to be performed include: breasts, kidneys, the liver, the pancreas, the prostate, the thyroid, lungs, ovaries and lymph nodes. Fine needle biopsy is a diagnostic tool used to evaluate organ or tumour tissue, and may also be used to establish whether or not certain treatments are working. It is normal for a local anaesthetic to be used to numb the area where the needle will be inserted. The thin hollow biopsy needle is inserted through the skin to the biopsy site. In current procedures, the needle may be inserted more than once for correct positioning or to obtain multiple samples.
When taking needle biopsies to identify potential breast tumours, it is normal practice for the surgeon to guide the biopsy needle into the area of concern by palpitating or feeling the lump, whenever this is physically possible, and then the needle may be located into the tumour based on this information. There is a high risk of false negatives occurring when taking biopsies in this manner, and it may be necessary to perform several needle biopsies in the region where the lump has been felt in order for there to be a good chance of locating the cancerous tissue.
If the lump is non-palpable, then the biopsy may be performed under image guidance, e.g. using ultrasound. However, even when ultrasound-guided needle biopsies are performed, it is normal to make several attempts at locating the cancerous site. Imaging using ionising radiation is also used to locate the biopsy needle inside the tumour. Fluoroscopy, where X-rays are directed onto a fluorescent plate, which is linked to a television camera, is used to see live images of the insertion of the biopsy needle on a monitor, and to establish the most appropriate position to take the biopsy. Computer tomography (CT) or computer aided tomography (CAT), where a scanner is used to rotate X-rays around the patient, is also used to guide the biopsy needle. This form of image guidance has the obvious drawback of exposing the patient to potentially harmful doses of X-ray radiation. Other drawbacks include: X-ray imaging procedures are expensive and can be time consuming, they require specialist support to drive the equipment, and they are not always successful in locating the cancerous site.
Needle biopsies are widely used and accepted as a safe and reliable test for the determination of the manifestation of cancer in the human body, but currently used methods may lead to cancerous cells being spread around the body when the biopsy needle is withdrawn. The concern is that during the procedure of removing the needle from the biopsy site, malignant cells may break away from the tumour and be deposited along the needle track that contains healthy tissue. This may lead to seeding and the development of new tumours. It has been reported1 that a needle biopsy may increase the spread of cancer by 50% compared to patients who undergo lumpectomies. 1 in an article by Dr Joseph Mercola (http://www.mercola.com/2005/apr/16/needle biopsy.htm)
Cases have been reported where the use of fine needle biopsies to diagnose liver tumours has led to metastases seeding along the biopsy needle track. In one clinical review2 it is stated that the occurrence of seeding is likely to be the cause of the death of a particular individual described in the case study. 2 Metcalfe M. S, Bridgewater F. B. G., Mullin E. J., and Maddern G. J., Br. Med. Jou., 328, 28 Feb. 2004, pp. 507-508